Chemistry Questions

Which  of  the  following  substances  cause temporary hardness in water?

1. Mg(HCO3)2

2. Ca(HCO3)2

3. CaCl2

4. MgSO4

Which one of the following statements would be INCORRECT to use?

Generally covalently bonded molecules ______.

I. have high boiling and melting point as compare to ionically bonded molecules

II. poor conductors of electricity

III. have weak intermolecular force

Isotopes have ______.

I. similar physical quantities and different chemical properties

II. different physical properties

III. similar chemical properties

A ‘breath test’ used by traffic police to check drunken driving uses ____?

Lime water becomes white due to which gas?

Atmosphere of Venus mostly contains which of the following gases? 

Ionic compounds ______.

I. have high boiling point

II. have high melting point

III. conduct electricity in solution